Medical termination of pregnancy during the second versus the first trimester and its effects on subsequent pregnancy

The objective was to compare the risks of preterm birth, low birth weight, small for gestational age (SGA) infants and placental complications in subsequent pregnancy after second vs. first trimester medical termination of pregnancy (MTOP) in primigravid women.

A total of 88,522 women who underwent termination of pregnancy during 2000-2009 were identified using Finnish health registers. Of them, primigravid women who underwent MTOP and had subsequent pregnancy ending in live birth up to the end of 2009 (n=3843) were included in the study. The incidences and risks of preterm birth, low birth weight, SGA infants and placental complications after first- (n=3427) vs. second-trimester MTOP (n=416) were compared.

Differences between the study groups in the incidences of preterm birth (3.9% in both groups), low birth weight (3.9% in the second- vs. 3.2% in the first-trimester group), SGA infants (2.4% vs. 2.5%) and placental complications (1.9% vs. 2.6%) were statistically insignificant. Second-trimester MTOP was associated with similar risks of preterm birth, low birth weight, SGA infants and placental complications compared with first-trimester MTOP after adjustment for background characteristics. After second-trimester MTOP, 51.2% of women underwent surgical evacuation, and 4.3% were diagnosed with infection. The differences in the risks of preterm birth, low birth weight, SGA infants and placental complications were statistically insignificant between women with vs. without these complications following second-trimester MTOP.

Second-trimester MTOP among primigravid women did not increase the risks of preterm birth, low birth weight, SGA infants or placental complications in subsequent pregnancy compared with first-trimester MTOP.

The present study suggests that medical termination of pregnancy in primigravid women during second vs. first trimester does not increase the risks of adverse outcomes in subsequent pregnancy and delivery. The data are of value when counseling women undergoing second-trimester TOP.